Rogue RDP Connections
Since I noticed my ethernet connection performance as being saturated on my Windows 2012 R2 server, I ran the netstat command & noticed alot of ip addresses having established connections to 3389. When looking further, I see that these ip addresses are from many different countries like korea, china, russia, turkey... What can I do to prevent these rogue connections? Are they authenticating to my server? Could there be an app on the server thats allowing this?
See only one example below:
C:\Windows\system32>netsta
TCP 0.0.0.0:3389 0.0.0.0:0 LISTENING
TCP 192.168.220.20:3389 81.25.47.69:57070 ESTABLISHED
TCP 192.168.220.20:3389 81.25.47.69:57184 ESTABLISHED
See only one example below:
C:\Windows\system32>netsta
TCP 0.0.0.0:3389 0.0.0.0:0 LISTENING
TCP 192.168.220.20:3389 81.25.47.69:57070 ESTABLISHED
TCP 192.168.220.20:3389 81.25.47.69:57184 ESTABLISHED
Check your server event security logs and see if someone got authenticated. Is this server hosted locally or cloud? like azure. Check your firewall
Mission Critical Engineer
You could use
C:\> netstat -nao | find "3389"
to find the owning process id (ie: which process listens on port 3389)
TCP 192.168.178.10:3389 192.168.178.69:53236 ESTABLISHED 1396
and then try
C:\> tasklist | findstr 1396
to find the name of PID 1396. In my case this is 'svchost.exe' which is normal for 'real' RDP connections.
In your case it might be a different process.
Regards,
Dirk-Jan
C:\> netstat -nao | find "3389"
to find the owning process id (ie: which process listens on port 3389)
TCP 192.168.178.10:3389 192.168.178.69:53236 ESTABLISHED 1396
and then try
C:\> tasklist | findstr 1396
to find the name of PID 1396. In my case this is 'svchost.exe' which is normal for 'real' RDP connections.
In your case it might be a different process.
Regards,
Dirk-Jan
Information Security Officer
Use wireshark for analyzing the network. and if you want to find out how they are connecting ., try to do a Vulnerability assessment on your server. And first thing first, If you dont want your RDP service for the server , you can disable it.
